Jacinda Ardern's visit to the University of Canterbury has led to an angry confrontation after a student turned up with a 'Vote National' sign.

Ms Ardern was mobbed by hundreds of students in the recreation room of the University, echoing similar sights seen at other campuses around the country.

While that was happening, National supporter Jacob Putson turned up with his homemade blue sign.

WATCH THE FULL CONFRONTATION ABOVE 

After being booed by many in the mob of Labour supporters, one student took particular offence to the sign and confronted Mr Putson - pointing his finger in his chest and asking him "who else in the room supported National."

He then ripped Mr Putson's sign off him, throwing it on the ground and coming close to shoulder bumping him.

Mr Putson later said that the confrontation demonstrates the left don't respect the right to free speech.

"I'm not ripping the signs off the Labour Party," he said.

"The left try to monopolise free speech and morality. I think it is an attack of free speech and free expression."

The confrontation made for a minor distraction for the huge crowds hoping to get a glimpse of Jacinda Ardern. 

"The right are much more tolerant of the left's views...that man there was absolutely in the wrong," Mr Putson said.